Boat dry docking device

ABSTRACT

A boat dry docking device for small craft consisting of an elongated boat supporting frame adapted to be disposed longitudinally in the boat well of a floating dock and to be pivoted to said dock at the closed end of said well for vertical movement, whereby the end thereof at the open end of the well may be dropped below water level, to receive a boat thereon, or raised to elevate said boat above water level, a flotation tank open at its bottom secured to the frame remotely from its pivot, mechanism operable to deliver air to or exhaust it from the tank whereby to raise or lower the frame, and reinforcing devices for preventing lateral tilting and lateral sidesway of the free end of the frame.

United States Patent 91 Williams Apr. 17, 1973 BOAT DRY DOCKING DEVICEBarney V. William, Route No. 1, Grove, Okla.

[22] Filed: Sept. 16, 1971 [21] Appl. No.: 180,976

[76] Inventor:

l/l968 Rutter ..6l/65 Primary Examiner-J. Karl Bell Att0rney-John A.Hamilton ABSTRACT A boat dry docking device for small craft consistingof an elongated boat supporting frame adapted to be disposedlongitudinally in the boat well of a floating dock and to be pivoted tosaid dock at the closed end of said well for vertical movement, wherebythe end thereof at the open end of the well may be dropped below waterlevel, to receive a boat thereon, or raised to elevate said boat abovewater level, a flotation tank open at its bottom secured to the frameremotely from its pivot, mechanism operable to deliver air to or exhaustit from the tank whereby to raise or lower the frame, and reinforcingdevices for preventing lateral tilting and lateral sidesway of the freeend of the frame.

7 Claiim, 8 Drawing Figures PATENTED 1 3,727, 415

SHEET 1 BF 3 g INVENTOR.

Bar/my V. Ml/iam:

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PATENTED APEH 71973 IN VEN TOR. Ear/ray I! M'l/Amzs Arm/way.

BOAT DRY DOCKING DEVICE This invention relates to new and usefulimprovements in boat docks for small craft, and has as its principalobject the provision of an attachment for a boat clock by means of whicha boat moored at said dock may easily and conveniently be elevated andmaintained out of the water and dry when not in use. Obviously, such adevice provides great savings to boat owners in the reduction of rust,corrosion, marine growths, and other water damage, and in the reductionof resulting repair and maintenance costs. Many boat owners provide fordry storage of their boats in the winter off-season when their boats arenot used for extended periods of time, but not usually in day-to-dayperiods of non-use during the summer season, due to the trouble andexpense of such storage.

Accordingly, it is also an object of the present invention to provide adevice of the character described constituting a simple, inexpensiveattachment adapted to be affixed to nearly any common boat dock, andwhich may be operated with no more powerful equipment than a smallelectric motor, or even manually. To this end, the device consists of anelongated boat supporting frame adapted to be arranged longitudinally inthe boat well of a dock, and pivoted to said dock on a horizontaltransverse axis at the forward or closed end of the well. A flotationtank secured to said frame beneath the rearward end portion thereof, andmeans for selectively delivering air to or exhausting it from said tank,provide that the rearward end of the frame may be dropped below waterlevel, whereby a boat may be positioned thereon while still floating andselfpowered, and raised to elevate said boat free of the water.

Another object is the provision of a device of the character describedhaving novel means for bracing said frame with respect to the clock,whereby a lighter construction may be used with no danger that the boatwill shift or move with respect to the dock when the water is rough.Such movement causes possible damage to the frame, the dock, and theboat itself.

A further object is the provision of a dry-docking device of thecharacter described which is readily adjustable to handle boats ofdifferent lengths, and to be applied to boat docks having boat wells ofdifferent widths, and different degrees of freeboard clearance.

Other objects are simplicity and economy of construction, and efficiencyand dependability of operation.

With these objects in view, as well as other objects which will appearin the course of the specification, reference will be had to theaccompanying drawing, wherein:

FIG. 1 is a top plan view of a boat dock, partially broken away, showinga dry docking device embodying the present invention mounted operativelythereon,

FIG. 2 is a sectional view taken on line II-II of FIG. 9

FIG. 3 is a fragmentary view similar to FIG. 2, but showing theboat-supporting frame lowered to a position for receiving a boatthereon,

FIG. 4 is an enlarged, fragmentary sectional view taken on line IVIV ofFIG. 1,

. FIG. 5 is an enlarged, fragmentary sectional view taken on line V-V ofFIG. 1,

FIG. 6 is an enlarged, fragmentary sectional view taken on line VI-Vl ofFIG. 1,

FIG. 7 is a fragmentary sectional view taken on line VII-VII of FIG. 6,and

FIG. 8 is an enlarged fragmentary sectional view taken on line VIIIVIIIof FIG. 2.

Like reference numerals apply to similar parts throughout the severalviews, and the numeral 2 applies generally to a boat dock consisting ofa horizontal platform 4 supported by flotation blocks 6 in the water 8,and having a notch 10 constituting a boat well formed therein. Said boatwell has generally parallel sides, as shown in FIG. 1, is closed at itsforward end, and opens at its rearward end through an edge of the dock,for receiving a boat therein. The detailed construction of the dock isnot pertinent to the present invention, and is not shown.

The dry docking device forming the subject matter of the presentinvention includes an elongated frame indicated generally by the numeral12 and extending longitudinally in boat well 10, midway between thesides of said well. Said frame includes a pair of longitudinallyextending parallel side rails 14, formed of tubular stock, and rigidlyinterconnected at intervals along their length by cross bars 16, saidcross bars being of V- shape as shown in FIG. 5. A boat cradle indicatedgenerally by the numeral 18 is carried by said frame. As shown, saidcradle consists of a pair of wooden planks 20 with their rearward endsdisposed respectively over the rearward ends of frame side rails 14, andconverging forwardly, being supported in slightly spaced relation abovethe frame by brackets 22 affixed to said frame. However, said cradle maytake many forms, all considered to be within the scope of the presentinvention.

The forward end portions of frame siderails 14 are angled upwardly, asshown in FIG. 2. A plate 24 is mounted for adjustable movement along theupwardly angled portion of each side rail, by means of a pair of U-bolts26. A tubular sleeve 28 is welded to each of plates 24, said sleevesbeing coaxial and rotatably engaged on a horizontal transverse shaft 30.One end of said shaft is welded to a plate 32 affixed to dock platform4, and the other end portion of said shaft is axially slidable in abracket 34 also affixed to platform 4. This permits the shaft to bemounted on the clock when the boat well 10 is of different widths, andthe frame to be transversely centered in the well by sliding sleeves 28along the shaft. When thus centered, further movement of said sleevesalong the shaft is prevented by a pair of collars 36 mounted on saidshaft and secured thereon by set screws 38. The vertical adjustment ofthe frame provided by U-bolts 26 permits adjustment of the device todocks wherein the top surface of platform 4 is disposed at differentdistances above the water level. Preferably, the adjustment is such thatwhen frame 12 is horizontal, as in FIG. 2, it is disposed just above thewater level.

A V-shaped buffer 40, adapted to engage the prow of a boat supported oncradle 18, is disposed adjacent the forward end of the frame. Saidbuffer is carried by a forwardly extending bar 42 which is adjustablysecured by a U-bolt 44 to a cross bar 46 extending between and affixedto the upwardly angled portions of side rails 14. The bow line of theboat may be tied to the forwardmost cross bar 16 of the frame, to holdits bow firmly against buffer 40.

A cylindrical flotation tank 48 is disposed beneath the rearward endportion of frame 12, the axis of said tank being horizontal andtransverse to said frame. Said tank is provided at its lowermost partwith one or more water holes 50 (see FIG. 2) and has affixed to the topthereof a pair of brackets 52. Each of said brackets is affixed to achannel iron slide 54 which is engaged slidably on one of side rails 14.Said slides may be moved adjustably along said side rails, whereby tomove tank 48 forwardly or rearwardly with respect to the frame, and arereleasably secured thereon by U- bolts 56. This adjustment permitsadaptation of the device to longer or shorter boats, it being preferablethat the tank be disposed so that a major portion of the weight of theboat be supported by the tank, not the dock, to relieve strains on thedock. Air is delivered to tank 48 by a flexible hose 58, one end of saidhose being connected into the upper portion of said tank by an elbowfitting 60, and its opposite end being interconnected into one of thetubular side rails 14 of the frame, just forwardly of the tank, bymeansof a blind T-fitting 62 inserted in said side rail, all as best shown inFIG. 4. The hose of course permits forward and rearward adjustment ofthe tank as described above.

Air is delivered through side rail 14 and hose 58 to tank 48 by an airpump 64 affixed to the extreme forward and upper end of the associatedframe side rail, said pump being operated by an electric motor 66, whichmay conveniently be structurally integrated with the pump as shown, andto which electric current is supplied by a flexible cable 68. Connectedinto the associated side rail 14, adjacent pump 64 is a valve 70 havingan operating handle 72 which manipulates an interior gated plug 74 ofsaid valve (see FIG. 8) whereby the valve may be set to connect pump 64with tank 48, as shown by the arrows in FIG. 8, or to seal off allconnection to the tank, or to vent the tank to atmosphere through a sideoutlet 76 of the valve.

To prevent or minimize torsionaltwisting of frame 12 about itslongitudinal axis, which can occur as a result of wave action when thewater is rough, there is provided a stabilizer crank 78 of U-shape, saidcrank including apair of parallel side arms 80, each pivoted on ahorizontal axis transverse to the frame, as at 82, to a bracket 84secured at 86 to dock platform 4, at one side of boat well 10, and arigid connecting rod 88 joining the free ends of said side arms andextending horizontally and transversely beneath channel iron slides 54,just rearwardly of tank brackets 52. Said rod is secured slidablyagainst said slides by keeper bars 90 which are elongated longitudinallyof the frame and affixed at their ends to slides 54, whereby to permitconnecting rod 88 to move forwardly and rearwardly along said slides.The crank prevents either of frame side rails 14 from rising or fallingmore than the other, and thus greatly inhibits any tendency of the frameto twist about its longitudinal axis. Connecting rod 88, as best showninFIGS. 1 and 6, is adjustable in length to accommodate the crank to boat.wells of different widths, consisting of a tubular section 88A and asection 88B telescoped slidably in said tubular section. Once adjusted,sections 88A and 88B are secured no'n-rotatably together by set screw92, in order that the crank may better perform its anti-torsionfunction. Crank brackets 84 should preferably be affixed to the dockplatform after slides 54 have been adjusted to determine the position oftank 48.

To prevent lateral sidesway of the rearward end of frame 12, relative tothe dock, there is provided a strut bar 94 extending horizontally andtransversely beneath said frame at the rearward end thereof. As bestshown in FIGS. 1 and 5, said strut includes a tubular central section 96rigidly welded or otherwise affixed to the rearrnost cross bar of theframe, and a pair of end sections 98 mounted telescopingly and slidablyin the respective ends of said central section and projecting outwardlytherefrom, said end sections being adjustably affixed in said centralsection by set screws 100, whereby the length of the strut may beadjusted. When properly adjusted, said strut engages snugly but slidablybetween a pair of vertical plates 102 affixed at their upper ends todock platform 4 at respectively opposite sides of boat well 10. Saidplates extend well below the water level, and are curved arcuately outwardly at their lower ends, as indicated at 104. The bracing andreinforcing of frame 12 by stabilizer crank 78 and strut 94 permits saidframe to be built of much lighter, and hence less expensive, materialsthan would otherwise be required. Affixed to the strut adjacent each endthereof is an eye 106 into which one end of a linked chain 108 isconnected. As will appear, each of said chains may be extended upwardly,and engaged non-slidably in a notch l 10 provided therefor in the topend of the associated plate.

In operation, a boat is dry docked by releasing chains 108 from notches110 and setting valve to exhaust air from tank 48 through outlet 76 ofthe valve. As air leaves the tank and is replaced by water therein, thebuoyancy thereof decreases and it sinks deeper into the water, causingframe 12 to pivot downwardly at its rearward end about shaft 30, asshown in FIG. 3, to a position well below the water level. Stabilizercrank 78 limits the downward pivoting of the frame. A boat may then bepiloted into boat well 10, floating and under its own power, to positionit above said frame and boat cradle 18, until the boat prow engagesbuffer 40 and is secured thereagainst by tying its bow line to theforwardmost frame cross bar 16. Valve 70 is then set as shown in FIG. 8to connect air pump 64 to tank 48, and said pump is actuated to forceair into the tank. As air enters the tank and displaces water therefromthrough holes 50, the buoyancy of the tank increases and it rises topivot frame 12 upwardly, first causing cradle 18 to engage the boatbottom, then raising the boat itself. As the frame rises, strut 94engages and is centered between plates 102. The tank of course does notfloat freely in a stabilized condition until at least a portion thereofis raisedabove the water level, and at this time the boat hull has beenlifted completely above the water, and it may be elevated still further,by pumping more air into the tank, to elevate even the propeller screwabove the water. Valve 70 is then set to seal the tank, and the dockingmay if desired be viewed as completed. However, at this time the boat issupported partially by shaft 30, but the major portion of its weight issupported in the water by the buoyancy of tank 48. Thus rough weathercan cause vertical bobbing of frame 12 and the boat due to wave actionin the water. This bobbing is accompanied by violent strains of manytypes and can result in damage both to'the docking device and to theboat. Moreover the continued support of the boat is dependent on themaintenance of full air pressure in the tank, which requires a perfectsealing of the air system. Such a perfect seal is difficult if notimpossible to maintain over long periods of time, so that the airgradually leaks away and the boat is lowered into the water. For thesereasons, it is preferred that once the boat has been elevated fully asalready described, the latch means constituting chains 108 is broughtinto play, chains 108 being engaged in notches 110, and valve 70operated to vent at least some of the air pressure from tank 48. In thismanner, all or any desired part of the boat weight previously supportedby tank 48 is transferred to chains 108, and hence directly to theclock. The boat and the dock are thus effectively joined into a singleunit, with no relative movement therebetween, even in rough water, andtogether they can ride out a violent storm with little danger of damage.Also, the continued support of the boat is no longer dependent on themaintenance of air pressure in the tank. However, it is stillpreferable, in order to relieve strains on the dock, that as much of theboat weight as possible be carried by the flotation tank, and thereforeair is preferably exhausted from the tank, and boat weight therebytransferred to chains 108, only in sufficient degree to prevent bobbingof the boat.

Thus it will be apparent that a dry docking device having severaladvantages has been produced. lt elevates a boat completely out of thewater, providing all of the advantages of dry storage, but issufficiently simple and economical to be available even to individualsmall boat owners. For power operation, it requires only a small,inexpensive motor to operate the air pump, and the air pump could evenbe manually operated if desired. It may be freely adapted to handleboats of different weights and lengths, and to be applied to dockshaving wells of different widths, and different amounts of freeboardclearance.

While I have shown and described a specific embodiment of my invention,it will be readily apparent that many minor changes of structure andoperation could be made without departing from the spirit of theinvention.

What I claim as new and desire to protect by Letters Patent is:

l. A boat dry docking device comprising:

a. an elongated frame adapted to be disposed longitudinally in the boatwell of a boat dock,

b. means for mounting said frame on said clock for pivotal movement on ahorizontal transverse axis at the end thereof remote from the open endof said boat well,

. a boat-supporting cradle mounted on said frame,

. a flotation tank open at its bottom,

e. means mounting said flotation tank on said frame beneath thevertically movable end portion thereof, said means being adjustable tomove said tank longitudinally along said frame, whereby said device maybetter accommodate boats of different lengths, and

f. an air system operable to selectively deliver air under pressure to,or to exhaust said air frame, said tank whereby to selectively raise thevertically movable end of said frame above, or to lower it below, thelevel of the water in which said tank is supported.

2. A device as recited in claim 1 wherein said means mounting saidflotation tank on said frame comprises:

a. a slide member mounted on said frame for movement longitudinallytherealong, said tank being affixed to said slide, and

b. means operable to secure said slide immovably on said frame at anypre-determined position.

3. A boat dry docking device comprising:

a. an elongated frame adapted to be disposed longitudinally in the boatwell of a boat dock,

b. means for mounting said frame on said dock for pivotal movement on ahorizontal transverse axis at the end thereof remote from the open endof said boat well,

c. a boat-supporting cradle mounted on said frame,

d. a flotation tank open at its bottom,

e. means mounting said flotation tank on said frame beneath thevertically movable end portion thereof,

f. an air system operable to selectively deliver air under pressure to,or to exhaust said air from, said tank whereby to selectively raise thevertically movable end of said frame above, or to lower it below, thelevel of the water in which said tank is supported, and

g. stabilizing means comprising a U-shaped crank having parallel sidearms disposed respectively at opposite sides of said frame, within saidwell, and extending parallel to the plane of vertical movement of saidframe, and a connecting rod extending horizontally and transverselybeneath said frame, and rigidly interconnecting a pair of correspondingends of said side arms; means for pivoting the opposite ends of saidside arms to said dock on a horizontal transverse axis; and keeper meanscarried by said frame and engaging said connecting rod whereby toprevent vertical movement of said connecting rod relative to said frame,but to permit movement of said connecting rod longitudinally of saidframe.

4. A device as recited in claim 3 with the addition of anti-sideswaymeans comprising:

a. an elongated rigid strut affixed to the vertically movable end ofsaid frame and extending horizontally and transversely outwardly fromthe sides thereof to points adjacent the sides of said boat well, and

b. a pair of vertical plates adapted to be affixed to said dockrespectively at opposite sides of said well, and to extend below thewater level, the ends of said strut engaging snugly but slidably betweensaid plates.

5. A device as recited in claim 4 wherein said frame mounting means,said stabilizing crank connecting rod and said strut are all adjustablein length transversely of said frame, whereby to render said deviceadaptable for use in connection with boat docks having boat wells ofdifferent widths.

6. A boat dry docking device comprising:

a. a elongated frame adapted to be disposed longitudinally in the boatwell of a boat dock,

b. means for mounting said frame on said dock for pivotal movement on ahorizontal transverse axis at the end thereof remote from the open endof said boat well,

c. a boat-supporting cradle mounted on said frame,

d. a flotation tank open at its bottom,

whereby to support said frame independently of the buoyancy of saidflotation tank.

7. A device as recited in claim 4 with the addition of a pair of chainssecured to said strut respectively adjacent the opposite ends thereof,said chains being extendable upwardly from said strut and any link ofeach being releasably but securely engageable in a notch providedtherefor in the upper end of the associated plate, whereby to supportsaid frame from said dock independently of said flotation tank.

1. A boat dry docking device comprising: a. an elongated frame adaptedto be disposed longitudinally in the boat well of a boat dock, b. meansfor mounting said frame on said dock for pivotal movement on ahorizontal transverse axis at the end thereof remote from the open endof said boat well, c. a boat-supporting cradle mounted on said frame, d.a flotation tank open at its bottom, e. means mounting said flotationtank on said frame beneath the vertically movable end portion thereof,said means being adjustable to move said tank longitudinally along saidframe, whereby said device may better accommodate boats of differentlengths, and f. an air system operable to selectively deliver air underpressure to, or to exhaust said air frame, said tank whereby toselectively raise the vertically movable end of said frame above, or tolower it below, the level of the water in which said tank is supported.2. A device as recited in claim 1 wherein said means mounting saidflotation tank on said frame comprises: a. a slide member mounted onsaid frame for movement longitudinally therealong, said tank beingaffixed to said slide, and b. means operable to secure said slideimmovably on said frame at any pre-determined position.
 3. A boat drydocking device comprising: a. an elongated frame adapted to be disposedlongitudinally in the boat well of a boat dock, b. means for mountingsaid frame on said dock for pivotal movement on a horizontal transverseaxis at the end thereof remote from the open end of said boat well, c. aboat-supporting cradle mounted on said frame, d. a flotation tank openat its bottom, e. means mounting said flotation tank on said framebeneath the vertically movable end portion thereof, f. an air systemoperable to selectively deliver air under pressure to, or to exhaustsaid air from, said tank whereby to selectively raise the verticallymovable end of said frame above, or to lower it below, the level of thewater in which said tank is supported, and g. stabilizing meanscomprising a U-shaped crank having parallel side arms disposedrespectively at opposite sides of said frame, within said well, andextending parallel to the plane of vertical movement of said frame, anda connecting rod extending horizontally and transversely beneath saidframe, and rigidly interconnecting a pair of corresponding ends of saidside arms; means for pivoting the opposite ends of said side arms tosaid dock on a horizontal transverse axis; and keeper means carried bysaid frame and engaging said connecting rod whereby to prevent verticalmovement of said connecting rod relative to said frame, but to permitmovement of said connecting rod longitudinally of said frame.
 4. Adevice as recited in claim 3 with the addition of anti-sidesway meanscomprising: a. an elongated rigid strut affixed to the verticallymovable end of said frame and extending horizontally and transverselyoutwardly from the sides thereof to points adjacenT the sides of saidboat well, and b. a pair of vertical plates adapted to be affixed tosaid dock respectively at opposite sides of said well, and to extendbelow the water level, the ends of said strut engaging snugly butslidably between said plates.
 5. A device as recited in claim 4 whereinsaid frame mounting means, said stabilizing crank connecting rod andsaid strut are all adjustable in length transversely of said frame,whereby to render said device adaptable for use in connection with boatdocks having boat wells of different widths.
 6. A boat dry dockingdevice comprising: a. a elongated frame adapted to be disposedlongitudinally in the boat well of a boat dock, b. means for mountingsaid frame on said dock for pivotal movement on a horizontal transverseaxis at the end thereof remote from the open end of said boat well, c. aboat-supporting cradle mounted on said frame, d. a flotation tank openat its bottom, e. means mounting said flotation tank on said framebeneath the vertically movable end portion thereof, f. an air systemoperable to selectively deliver air under pressure to, or to exhaustsaid air from, said tank whereby to selectively raise the verticallymovable end of said frame above, or to lower it below, the level of thewater in which said tank is supported, and g. latch means operable tosecure the vertically movable end of said frame releasably to said dock,whereby to support said frame independently of the buoyancy of saidflotation tank.
 7. A device as recited in claim 4 with the addition of apair of chains secured to said strut respectively adjacent the oppositeends thereof, said chains being extendable upwardly from said strut andany link of each being releasably but securely engageable in a notchprovided therefor in the upper end of the associated plate, whereby tosupport said frame from said dock independently of said flotation tank.